There is only one side of that story.
If you think God is a liar or "not a very nice person" then perhaps you need to read the Bible and see his personality reflected in the teachings and actions of his son....who represented his father perfectly.
Reading the bible, god's personality seems to be that of a jealous, vengeful, vindictive, psychopathic, narcistic, cruel, homophobic, barbaric sexist that has no problems with slavery and who holds eternal grudges.
A bit Trumpian actually... a man-child who demands to be worshipped and loved and who, in his narcistic delusions, wants to punish everyone that doesn't.
That doesn't sound "nice" to me at all. In fact, it's pretty much the definition of a
horrible personality. It's going to be very difficult to find a personality that's even worse.
God has fully planned to do just that, as it is written in the scriptures, but not until he has used the devil to flush out all those whose thinking and actions do not align with God's.
You have just acknowledged that which you previously called horrible... which is that god uses satan as a pawn to punish all those that he can convince. So yes, you actually do agree with the idea that satan does exactly what god wants him to do.
If god didn't want satan to lure humans over to his team, then the omnipotent god COULD stop him.
The fact that he doesn't either means that he can't or that he doesn't want to.
If he can't, then he ain't as powerful as you thought he was (and then he also couldn't do it in the future)
If he simply doesn't want to, then at best it means he doesn't care. At worst, he in facts wants satan to do what he does.
Those seem to be the only options.
All humanity are being tested as to fitness for citizenship in God's incoming Kingdom.
Exactly like
@Eddi said, which you disagreed to and called "horrible".
You're using different words, but you are saying the same thing. Humans are being tested and satan is part of the test. Aka, satan is doing what god wants him to do.
We all have to ask ourselves....Am I good citizenship material? What does God think of me?...how can I know? How do I shape up in God's eyes?
Yes, the people in North Korea have to ask themselves that question all the time (about The Great Leader)
It's how dictators and tyrants keep their flock in line. Through fear.
Only insecure people with bad intentions need to resort to fear tactics to keep their following.